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http://www.npr.org/series/358046323/colors
National Public Radio ran a story today about Kodak Printer Control Tool a.k.a. Shirleys. The purpose of Shirleys were to provide a visual standard so that photo finishers could easily establish and maintain their color negative film/print workflows. To support this Kodak provided a negative series made at normal, over, and under exposures. Also, accompanying the set there was a color print of each of the negatives.
Until about 1990 this was done with actual camera originated film negatives. A great deal of care was taken in making sure that the film was typical of film in the marketplace and the film process was representative of a well-maintained yet typical film process.
I thought APUG readers would be interested in how this need progressed from photographing the original seen thousands of times to creating negatives using digital imaging in also how it was used to design modern films
By the 1990s image simulation and film writers had progressed to the point that it was possible to provide standard negative sets that would be representative of trade quality but with far less variability in the population of the control tool sets.
These digital standard negatives were made by photographing the original scene, similar to the one shown in the article. This was done on 8 x 10 Ektachrome 64 Film. The transparency was then scanned and "unbuilt" to create a master file. The image was then rebuilt to reflect the characteristics of the particular color negative film and a typical color negative film process and written on to 35mm and 120-size film using a production film writer. The films from the film writer and a standard print were provided to consumer photo finishers and professional processing laboratories.
The same in building and rebuilding techniques were used to design PORTRA Films as well as other Kodak films that were introduced after 2000. These techniques allowed film designers to modify the various characteristics of the film and paper to produce the desired final results. Before the use of such simulation techniques it was necessary to actually make and coat emulsions in order to demonstrate different image characteristics. It required a great deal of effort to create the system but once this was done the input parameters could be incrementally modified to demonstrate the influence on the final result. Once the aim was established calculations were made to determine the required characteristics of the film. These characteristics would include curve shape, spectral sensitivity, color masking, printing density etc. Then the film builder was given the task of creating a film that satisfies these requirements.
The acceptance of PORTRA Films demonstrates the success of the technique.
Bob Shanebrook
author of "Making KODAK Film"
National Public Radio ran a story today about Kodak Printer Control Tool a.k.a. Shirleys. The purpose of Shirleys were to provide a visual standard so that photo finishers could easily establish and maintain their color negative film/print workflows. To support this Kodak provided a negative series made at normal, over, and under exposures. Also, accompanying the set there was a color print of each of the negatives.
Until about 1990 this was done with actual camera originated film negatives. A great deal of care was taken in making sure that the film was typical of film in the marketplace and the film process was representative of a well-maintained yet typical film process.
I thought APUG readers would be interested in how this need progressed from photographing the original seen thousands of times to creating negatives using digital imaging in also how it was used to design modern films
By the 1990s image simulation and film writers had progressed to the point that it was possible to provide standard negative sets that would be representative of trade quality but with far less variability in the population of the control tool sets.
These digital standard negatives were made by photographing the original scene, similar to the one shown in the article. This was done on 8 x 10 Ektachrome 64 Film. The transparency was then scanned and "unbuilt" to create a master file. The image was then rebuilt to reflect the characteristics of the particular color negative film and a typical color negative film process and written on to 35mm and 120-size film using a production film writer. The films from the film writer and a standard print were provided to consumer photo finishers and professional processing laboratories.
The same in building and rebuilding techniques were used to design PORTRA Films as well as other Kodak films that were introduced after 2000. These techniques allowed film designers to modify the various characteristics of the film and paper to produce the desired final results. Before the use of such simulation techniques it was necessary to actually make and coat emulsions in order to demonstrate different image characteristics. It required a great deal of effort to create the system but once this was done the input parameters could be incrementally modified to demonstrate the influence on the final result. Once the aim was established calculations were made to determine the required characteristics of the film. These characteristics would include curve shape, spectral sensitivity, color masking, printing density etc. Then the film builder was given the task of creating a film that satisfies these requirements.
The acceptance of PORTRA Films demonstrates the success of the technique.
Bob Shanebrook
author of "Making KODAK Film"
